Apparatus for joining the overlapping end of metal packaging strips



Des. 13, 1966 H. TIMMERBEIL 3,291,153

APPARATUS FOR JOINING THE OVERLAPPING END OF METAL PACKAGING STRIPS Filed necgz. 196s Dec. 13, 1966 H. TIMMERBEIL y APPARATUS FOR JOINING THE OVERLAPPING END OF METAL PACKAGING STRIPS 4 Sheets-Sheet 2 Draad f. fsf/f H. TIMMEREEHL APPARATUS FOR JOINING THE OVERLA 2&3 PPING END Dec. 13, 1966 OF METAL PACKAGING STRIPS Filed Dec. 2, 1963 4 Sheets-Sheet S De 13, 1966 H. TIMMERBEIL QE@ APPARATUS FOR JOINING THE OVERLPPING END l 0F METAL PACKAGING STRIPS Filed Dec. 42, 1965 4 Sheeis-Sheet L Filed Dec. 2, 1963, Ser. No. 327,372 Claims priority, applicatizon Germany, Dec. 5, 1962,

T 1s claims. (or. 14o-93.2)

The invention relates to an apparatus for joining the overlapping end of a strip of metal Wrapped around a package, by means of a sleeveless fastening, particularly of the type having at least one pair of stepped slits which are spaced transversely across the metal strip with the web Ibetween them pressed out of the plane of the strip, where the apparatus for forming the fastening has a plurality of dies, of which at least one is movable. Many different embodiments of such apparatus are known. In all known apparatus of this type the movable die is moved towards the package whereas the stationary dies are generally mounted on a base plate of the like resting on the package. These embodiments have the disadvantage that the force which is required to form the fastening, and which may be of considerable magnitude, is transmitted to the package through the base plate.

The invention aims to improve apparatus of this type and particularly to avoid the above-mentioned disadvantages. This is achieved in accordance with the inventron, in that the movable die or `dies are arranged to act 1n a direction away from the package. In the preferred embodiment of the invention two movable dies engage the underside of the metal strip on its two edges and press the strip against another die positioned above the strip to punch out the fastening from the underside. The apparatus according to the invention for joining the overlapping ends of a strip of metal `wrapped around the package has the advantage that the forces arising when the fastening is formed are to a large extent directed away from the package lby reason of the die or dies forming the fastening in the strip are moved away from and not towards the package.

In the preferred embodiment the movable dies are in the form of two-armed levers pivotally mounted on fixed shafts, one arm of each lever having a recess which comprises the die adapted to engage under the metal strap to be fastened, and the other arm being articulated to a pair of elbow levers which in turn co-operate with an operating means. It is also preferable to form the recesses in the two-armed levers which comprise the movable dies wit-h members which act as strippers when the fastening has been formed. In one embodiment of the invention the rear end of the elbow levers are pivotally mounted on a common pin which is slidably mounted in a longitudinal slot in the frame of the apparatus and which carries a roller engageable by a curved operating member operated by a handle. The outer face of the curved member, which engages the roller to operate the apparatus is differently shaped in different positions for a purpose hereinafter explained.

In another embodiment of the apparatus the two-armed levers, carrying the movable dies are connected at their outer ends to two levers, one of which is curved and one of which is straight and which in turn are pivotally connected to a plate secured on the operating handle. ln this construction the handle is pivotally mounted on the frame of the apparatus and the two connecting levers are pivoted to the handle so that when the apparatus is in the closed position the two pins are located approximately horizontally below the rotary axis of the joint head, and when the apparatus is in the opened position are approximately nited States Patent O ice vertical superimposed to the side of the same rotary axis.

It is also preferred to mount the fixed shafts of the two-armed levers above the end face of the stationary die. In this case opposed -sides of the stationary die have arcuate recesses.

In a third embodiment of the invention the two-armed evers are joined by a tension spring and their upper ends are engaged against a disc rotatable by an operating means about a horizontal axis, the two faces of the operating disc having cam surfaces adapted upon rotation of the disc to splay apart the ends of the two-armed levers thereby effecting the closing of the dies. The operating disc is eccentrically mounted and has a groove, preferably of T-shaped cross section around its periphery into which is engaged the upper die. The arrangement may also be reversed, i.e. the disc may be mounted concentrically and the groove formed eccentrically therein.

In this last embodiment, the yapparatus has three movable dies, two of them mounted pivotally so that they act on the strip of metal from the packaged side and the third die located above the strip, being adapted to move in a straight line.

Further according to the invention the die above the strip of metal is preferably made up of two parts which are movable relative to each other. In this way the width of the central die can be made to vary with the movement -of the operating means, the arrangement being such that the die is of smallest width when the apparatus is open thus permitting the metal strip to be easily released.

The number of fastenings made in the overlapping ends of the metal strip is immaterial. In the simplest case one is adequate. However, if there is a heavier load on the metal strip, it is advisable to align a plurality of fastenings longitudinally of the strip in known manner, the number `of part fastenings being variable. The plurality of fastenings may be produced simultaneously in which case a fastening apparatus is used having a plurality of movable dies, which .are operated hydraulically or pneumatically or by a motor. Of course, it is possi-ble to form a plurality of fastenings longitudinally of the strip one at a time with a single fastening apparatus, only in this case the apparatus must be used a corresponding number of times.

The apparatus according to the invention preferably also includes a tensioning or cutting device, so that the metal strip 4can be tensioned and so that the p-art leading ,back to the supply roll can be severed.

Vsimplest construction the apparatus is inserted by hand into one of the receivers. When the fastening has been formed, the apparatus is taken out and placed into the next receiver. Provision may also be made for the appa- `ratus to be transferred automatically from one receiver to another.

Further details of the invention are contained in the specific description.

Several examples of the invention are illustrated in the accompanying drawings, in which:

FIG. 1 shows -a fastening apparatus according to the invention in the form of pincers, in its open position with the strip of metal inserted;

FIG. 2 shows the same fastening apparatus, but in the closed position;

FIG. 3 shows another embodiment of a fastening apparatus in the form of tongs, in the closed position;

FIG. 4 shows the apparatus of FIG. 3 Vin the open position;

FIG. 5 shows a third embodiment of a fastening apparatus here for use with a mechanical operating device, 1n the closed position;

FIG. 6 shows the apparatus of FIG. 5 in the open position;

FIG. 7 is a part sectional view of part of an operating, tensioning and cutting means used in co-operation with the fastening apparatus shown in FIGS. 5 and 6;

FIG. 8 is a modified embodiment of a means for operating the fastening apparatus according to the invention, and

FIG. 9 is a plan view, partly cut away, of a finished fastening.

It should first be mentioned that in the apparatus shown in FIGS. 1 and 2 the device for tensioning the strip of metal has been omitted for the sake of simplicity. This device may be designed in known manner, nor need the fastening apparatus necessarily be associated with the tensioning means; instead the tensioning means and fastening means may be used independently of one another. As the fastening of a metal hoop is generally made up of a plurality of separate fastenings-for example of three f-astenings aligned lengthwise of the strip-a jig-like receiver may be used for the fastening apparatus. It is desirable for this receiver to be divided into a plurality of portions, into which the fastening apparatus is placed in succession. Steps may also be taken', however, to enable the fastening apparatus to be transferred automatically to the required portion of the receiver.

The fastening apparatus shown in FIGS. 1 and 2 has a rigid frame 10 on which all its components are mounted. Rigidly connected to the frame 10 is a handle, of which only the connecting pin 11 can be seen from the drawing. An operating lever 12 is articul-ated to the upper portion of the frame 10. Adjacent its pivot pin 13, the lever 12 has a curved portion 14, which is mounted substantially at right angles to the lever 12 so that the two parts together form an elbow lever. The curved member 14 has two different curved portions. The first portion 15, associated with the open position, is concave and the second adjoining portion 16 is convex. The pivotal movement of the lever 12 is limited in the open position by the curved portion being supported on part of the operating mechanism to be described hereinafter. In the opposite direc-` tion the movement of the lever 12 is limited by a stop 17 extending perpendicularly to the longitudinal direction of the handle and which strikes an abutment surface 18 on the frame 10.

The movable components of the fastening apparatus, which are used for deforming the strip of metal, comprise movable jaws which will now be described. Pivotally mounted on the frame 10 by means of pins 20 are two levers 19 which form jaws between which the strip of metal may be inserted. In the open position (FIG. 1) the two levers 19 are substantially parallel. Their upper ends are each connected by a pin 21 to an elbow lever 22 and the two elbow levers 22 are pivoted at their upper ends to a common pin 23 which slides in a longitudinal guide slot 24 in the frame 10. Also mounted on the frame 10 is a fixed die 25.

For purposes of forming the fastening, the two levers 19 have a jaw-like recess 26 which comprise of the movable dies. The opposite sides of these recesses are differently formed for a purpose which will be described hereinafter. The overlapping ends of the metal strip 27 to be fastened are placed between the two recesses 26 in the levers 19 and held in this position by a support or a spacer not shown. Parts of an associated tensioning device may be used for this purpose, and may keep the strip of metal a short distance -away from the package so that the strip can be gripped by the closing jaw portions 26. When the lever 12 is moved from the open to the closed position, the curved portion 15 initially engages a roller 28 mounted on the pin 23 thereby pressing the pin 23 downwards and acting on the levers 22. During this initial movement which takes place as the roller 28 runs over the curved portion 15, the overlapping ends of the metal strip 27 are brought to bear on the lower end face 29 of the die 25 by the two movable jaws. Little force is required during this phase of the formation of the fastening. Rapid movement is obtained due to the sharply curved face of the portion 15. In the next phase of the movement the metal strip 27 is deformed and the actual fastening formed. The special shape of the curved portion 16 takes account of the large amount of force used in forming the fastening. The portion 16 is less sharply curved and thus produces the greater force required. The movement of the curved portion 16 over the roller 28 further lowers the elbow levers 22 until the two levers 19 are approximately horizontal. In the course of this movement the sides 30 of the recesses 26, which constitute a pair of movable dies eng-age the opposite edges of the strip 27 from below. The portion grasped is defined by the side faces of the stationary die 25 which are perpendicular to the end face 29. As the levers 19 move into the horizontal position pairs of angled slits are formed substantially longitudinally of the metal strip and a web is simultaneously pressed out of the plane of the strip in between the two angled slits thus forming the fastening (see FIG. 2). It is of little importance whether the web or the two side portions are pressed out of the plane of the strip. Both parts could even be pressed out, although to different extents.

The finished fastening is of the known angled slit type which holds the overlapping end of the stri'p of metal 27 securely together. It should also be mentioned that when the levers 19 return to the starting position (FIG. l), the smaller sides 31 of the recesses 26 bear on the strip 27 from above and pushes it off the die 25. When the fastening apparatus has been fully opened it may either be lifted free or advanced longitudinally of the metal strip 27 ready to form another fastening in the same way in another part of the strip. There are various ways of returning the fastening apparatus to its starting position. Either springs or a forced guidance in the region where the two elbow levers 22 and the curved portions 15 and 16 are connected may be used.

FIGS. 3 and 4 show a modified embodiment fastening apparatus which operates on the same principle as the apparatus in FIGS. 1 and 2. The main difference is in the operating mechanics used. This is designed so as to provide positive guidance for the movable components. All the movable components of the fastening apparatus are mounted to a frame 70. In addition the frame has stationary components such as a die 71 and a handle 72. The latter is xed to the frame 70 and is used for holding it firm. The handle 72, of which only part is shown in FIGS. 3 and 4, comprises a tube fixed to the frame 70, for example by welding. In the region where the handle 72 is connected, the frame 70 has a stationary abutment 74 having a channelled recess in its upper end. The recess acts as `a support and stop for an operating lever 73.

The operating lever 73 comprises a tube axially telescoped on a peg 75 secured to a bracket 76. The tube 73 is fastened to the peg 75 by a pin 77. The bracket 76 is pivotally mounted on the frame 70 by means of a pin 78. Two levers 79 and 80 are articulated to the bracket 76 by means of pins 81. The lever 80 is angled in order that the open position shown in FIG. 4 can be reached. In the open position the upper part of the straight lever 79 thus fits into the angle of the other lever 80, The lower ends of the levers 79 and 80 are articulated to two levers 82 oppositely mounted on the frame 70 by means of pins 83. The levers 82 correspond to the levers 19 in FIGS. `1 and 2 and are each mounted on the frame 70 by pins 84. The only difference between the levers 22 and the levers 19 is their outline. However, the jaw-like recesses 85 correspond to those in FIGS. 1 and 2 and again opposite sides 86 and 87 are differently shaped.

The die 71 is different from the stationary die 25 in FIGS. 1 and 2. Apart from having a different outline and upwardly tapering sides, the die 71 has recesses 89 on both sides, which extend substantially perpendicularly from its end 88 and are approximately parallel to the side faces. These recesses form the active surfaces for the lateral limits for the die, and its base surface is arcuate. The radius of the arc is determined by the cutting edge of the pivotable lever 82.

The manner in which the fastening apparatus operates can be seen from FIGS. 3 and 4. In the open position (FIG. 4) the operating lever 73 is perpendicular. The pivot pins 81 of the levers 79 and 80 are practically vertically above one another and lie to one side of pin 78. The two levers 82 are inclined to the horizontal and the space between their free ends is large enough to enable the metal strip to be inserted between them without any difficulty. To form the fastening the lever 73 is pivoted towards the handle 72 until it engages the stop 74. This movement turns the bracket 76 clockwise, thus causing the two pins S1 to be displaced towards the pins 34. This in turn causes the two levers 82 to rotate about the pins S4 to reach a substantially horizontal position, as already described with reference to FIGS. 1 and 2. In this way the fastening is formed with the co-operation of the die 71.

FIGS. 5 and 6 show another embodiment of a fastening apparatus constructed somewhat similarly to that described in connection with FIGS. 1 and 2 but the apparatus is adapted to produce three fastenings lengthwise of the metal strip simultaneously. The mechanism for operating the apparatus is not shown. The apparatus could be operated manually using lever transmission, as in FIGS. 1 and 2, but it is advantageous for it to be operated by a motor, particularly if the metal strips are relatively thick. Such operating mechanisms may be constructed in known manner, so for the sake of simplicity no details will be given.

The frame carrying the movable parts of the apparatus is formed by four flat members 32 arranged in pairs. The two flat members in each pair are spaced parallel with their larger surfaces facing one another. The two flat members 32 of each pair are interconnected transversely by internal webs, while the two pairs are kept in the desired longitudinal positions by shafts which will be described hereinafter and other securing means. The members 32 each have a hole 33 in an upper part and these serve to connect the apparatus to the connecting parts of the apparatus which are not shown. Between the flat members 32 and on each side thereof are levers 34 corresponding to the levers 19 -of FIG. l. Three pairs of levers 34 are mounted longitudinally of the device. The levers 34 are pivotally mounted on shafts 35 which pass right through them and through the flat members 32. Each group consisting of a pair of flat members 32 and three levers 34 is associated with a shaft 35 extending from one side to the other of the group. The upper part of each lever 34 is forked, i.e. has two parallel limbs 36. Engaged in the gap between the two limbs 36 of the lever 34 are the end portions of levers 3'/ which are secured therein by shafts 38. The number of levers 37 provided is the same as the number of levers 34, but they are not all of the same shape. All the outside levers 37 are of the same shape, apart from the fact that at the opposite ends the levers 37 are mirror images of one another. As shown in FIG. 6, the outside levers 37 are stepped. The step in each lever 37 is approximately at the place of entry into the space between the two limbs 36. The portions of the levers 37 formed by the stepping extend parallel and their surfaces bear on adjacent members of the apparatus. The levers 37 in the centre of a group, on the other hand, are not stepped. Their surfaces are limited at one end by the two limbs 36 of the central lever 34 and at the other end by two slides 40. The slides 40 are also flat and one of each of their broad side is opposed to one of the fiat members 32. Altogether two shafts 39 extend through the slides, each of the two shafts 39 also forming a rotary shaft for one group of levers 37.

The lower ends of the levers 34 are shaped substantially like the lever 19 or 82 in FIGS. l to 4. The lower part of this lever arm has an angled portion 41 corresponding to the large side 30 or 86 of the jaw of the lever 19 or 82 respectively in FIGS. 1 to 4. The free edge acts as a press die. For this purpose the inner face of the angled portion 41 which comes into contact with the strip of metal is convexly curved.

The dies which are mounted between the pairs of levers 34 and the end face of which is to shape the web of the fastening is made up of two parts 42 and 43 which are movable relative to each other to vary the width of the die. The parts 42 and 43 of the die continue to bear on the levers 34 when the latter change their angular position, i.e. when the levers are positioned for forming the fastening. The purpose of this is to enlarge the gap between the two parts of the die. They thus take in a larger width, adapted to the movement of the opposed die. In this way the gap 44 is formed between the two parts 42 and 43. The width taken in by the two parts 42 and 43 together corresponds to the internal width between the paired angled portion 41 of the two-armed levers 34, i.e. a tool is formed, with which two slits can be made on both sides of a central web. When the fastening has been formed and the two-armed levers 34 opened, the two parts 42 and 43 of the die leave the splayed-out position described. They move towards one another, thus reducing their total widths and that of the gap 44. This step makes it easier for the fastenings in the strip of metal to be removed from the apparatus.

The fastening apparatus shown in FIGS. 5 and 6, also has a strip detent 45 acting in one direction. This is used for securing the free end of the strip, i.e. that forming the leading end of the hoop. The detent 45 has two clamping jaws 46, the oppositely directed surfaces of which are substantially saddle-shaped, with the gap in the saddle extending lengthwise of the strip of metal to be inserted. The saddle surfaces are provided with a toothing of saw-shaped section, extending transversely through the gap in the saddle, the saw teeth being directed away from the fastening apparatus. The clamping jaws 46 each co-operate with an inclined slat 47 to produce a clamping action, the two inclined slats in a detent being narrowed towards the fastening apparatus. With this construction a strip of metal lying in the strip detent and in the fastening apparatus can be prevented from moving in one direction but may be advanced in the opposite direction.

FIGS, 5 and 6 also show an abutment 48. In co-operation with a movable knife (not shown), the edge 49 of the abutment is used for severing the excess part of the strip when the fastening has been made.

FIG. 7 shows part of an apparatus having means for tensioning, fastening and severing a strip of metal. The actual fastening tool is shown at 50. The tool has been described in connection with FIGS. 5 and 6, so need not be elaborated on here. The abutment 48 associated with the fastening tool 50 co-operates with a pivotable knife 52, of which the actual knife edge is shown at 53. The knife 52 severs the strip of metal at the desired place in co-operation with the edge 49 of the abutment 48. The knife 52 pivots about the shaft 54 mounted in the frame of the apparatus. The knife 52 may be operated by a motor (not shown); manual operation is also possible, but in this case it is preferable to use levers.

The strip of metal forming the hoop is tightened in a tensioning means 55, which allows the strip to be tensioned as often as is desired. The tensioning means has a stationary strip holder 56 with a strip detent 57 acting in one direction. The latter substantially comprises toothing similar to saw teeth. The teeth are opposed to the direction of advance and become operatively connected to the strip of metal. The strip is tensioned by a second displaceable, i.e. reciprocating strip holder S8, which is also equipped with a strip detent 59 substantially corresponding to the detent 57. The strip is advanced in known manner by reciprocating the displaceable holder 58 longitudinally of it, this strip being held and advanced by the detent 59 when the holder moves in one direction. When the displaceable holder 58 moves away from the direction of advance, the strip of metal is held by the stationary detent 56, while the detent S8 is displaced towards the xed detent 56. On further tightening the strip is released from the fixed holder in the direction of advance, and the same process is repeated until the strip is sufficiently tensioned. Tensioning may be effected either manually or semi or fully automatically.

FIG. 8 shows a fastening apparatus according lto the invention with a modied operating means. The twoarmed levers 60 are rotatably mounted in parts 62 of the frame by means of shaft 61. In the region of their angled portions 63 they are similar to those in the preceding iigures, but the rear free end of the levers 60 bears on curved surfaces 64 of a disc 66 rotating about a shaft 65. The surfaces 64 take in the same angular range and are arranged in mirror image. The two rear free ends of the levers 60 are loaded by a spring 67. The disc 66 also has a T-groove 68 extending around its outer surface, in which a die 69 is guided by a guide member. As the disc 66 is mounted eccentrically, the height of the die 69 is varied as the disc rotates.

The fastening apparatus may operate with the true movement, namely the change in the angular position of the two two-armed levers 60 and the vertical reciproca-tion of the die 69, either overlapping or succeeding one another.

FIG. 9 shows an example of the finished fastening of a strip of metal 27. The construction and shape of the fastening are known, but it is produced in quite a different manner, for this fastening is made with one of the apparatus shown in FIGS. l to 8. The three parts fastening may, of course be produced in a different manner, for example being formed singly. The required number of parts-in this case three-is obtained merely by applying the apparatus several times in succession at the spacing between the individual parts longitudinally of the strip. An apparatus of this type has only one active pair of limbs. It is also possible, however, for the three parts of the fastening to be produced simultaneously. This may, for example, be done with an apparatus as shown in FIGS. and 6.

The part fastening are all shown in their closed position, i.e. tension has been exerted on the end of the strip of metal after the angled slits have been formed therein by the fastening apparatus. The conformation of the central web 90 located between two angled slits 91 arranged in pairs can be seen particularly clearly from the plan view. On both sides of the stationary die for forming the web 90, the free ends, the cutting edges of the movable limbs of the fastening apparatus are designed to t against the edges extending perpendicular to the end face of the fixed die. In other words, their end limits are of the same shape as the angled slits. At 92 pressure is applied to the strip of metal 27 in known manner. This positions the short edge formed in the severing process so that it cannot cause any injury to the operator.

As already mentioned, the embodiments shown are only examples of the invetnion. The invention is not restricted to these, and many other constructions are possible. Thus for example, the deforming means to be applied successively longitudinally of the strip of metal may differ from one another, in order to produce different sleeveless fastenings. The individual fastening tool need not become effective simultaneously; their movements may overlap, or they may act successively on the strip of metal. In the case of a three-pant fastening according to FIG. 9, the two outermost parts of the fastening may be formed first and may be brought into the close position when the apparatus has been removed. The central part of the fastening is formed only when this closed position has been reached. The function of the central part is to prevent backward displacement, i.e. unintential opening of the first two parts of the fastening. This part of the fastening may also be shaped differently from the one shown in FIG. 9. With hand-operated apparatus it is possible to align a plurality of such apparatus, in which case they will be operated in succession, with an advantageous effect on the power requirement. It is also possible, particularly for hand-operation for certain tong-like fastening apparatus to be associated with the tensioning means required for the strip of metal. are supplemented wtih jig-like receivers for the fastening apparatus. The apparatus can then be placed in the successive receivers. In this simple manner the fastening can always be formed at the desired place along the strip of metal. Steps may also be taken, however, to move the apparatus out of one receiver and into the next when one part of the fastening has been made, this being done for example, by means of a spring mechanism. And finally, a severing or tensioning means other than the one shown may be coupled to the fastening apparatus.

The .shoulders 93 may be deformed when the fastening has been tightened. This prevents the fastening from opening again, for the deformed shoulders 93 prevent any movement in the opening direction. One has a free hand as to whether all the shoulders or only some of the shoulders in a fastening are deformed. Deformation may be effected in one operation or in a plurality of successive operations.

When the slits 91 have been formed the end of the strip may be squeezed transversely to the length of the strip. This prevents the end from being lifted apart, but movement longitudinally of the strip is still possible, so that the shoulders 93 can be brought into their fastening position. If the fastening comprises several parts, squeezing may be effected in the region of all or only some of the parts.

If the strip of metal is stretched quite tightly about the package and then cut by the severing means, the edges of the slit `are bent when the part of the die associated with the severing 'means is opened. This bending is used to secure the fastening.

A cam control may also be provided for the knife 52. In this case the movement of the knife may be dependent 0n that of t-he parts of the die. If special tensioning equipment is provided apart from the actual fastening apparatus, the knife may be associated with this equipment. Special die will then .be used for the knife, for example in the form of two guide pins.

If the strip detent 45, shown in FIGS. 5 and 6 is used, it is also possible for one of the two overlapping ends of the strip to be held in position while the other remains movable. This is made possible by the wedge shape ofthe detent. The edge 49 of the opposed knife 48 may also be yroof-shaped.

Iclaim:

1. Apparatus for fastening overlapping ends of metal strip wrapped around a package by means of at least one fastening catch, comprising, in combination, a frame; at least one pair of rst die means pivotally mounted spaced from each other on said frame and having strip engaging face portions adapted to engage the overlapping str1ps at one face thereof; a third die means carried by said frame and arranged substantially centrally between said pair of first die means and having an end face smaller than the width of said overlapping strips, and adapted to engage said overlapping strips on a face thereof opposite said one face; and means carried by said frame and cooperating with said die means for moving the latter relative to each other in such a manner that said face portions of said rst die means move beyond said end face of said third die means so that the latter forms two slits through said overlapping strips extending sub- The tensioning means stantially in longitudinally direction of said strips spaced from longitudinal edges thereof and presses `out webs between said slits through said overlapping strips.

2. Apparatus according to claimll, wherein said die means :are shaped in such al manner that said slits formed by said die means are stepped for higher resistance against forcible separation of the yoverlapping strips.

3. Apparatus according to claim l, wherein said first die Imeans include double arm levers; and s-upport shafts iixed to said lframe which support shafts provide a mid pivot for said double arm levers.

4. Apparatus according to claim 3, wherein one lever end of each of said rstdie means is formed with an upper and a llower projection, the lower projection being adapted to enga-ge said metal strip from the .side of the package to be wrapped, the upper projection being adapted to `strip the metal strips from said second die means after said web has been pressed out.

5. Apparatus according to claim 3 and including a toggle lever for each pair of sai-d levers, said toggle lever having two links, each of which is pivoted to a common pivot at one end and to a respective one of said double arm levers at the other end; and operating means con nected to said common pivot of said links for moving said common pivot along a path, thereby forming said first die means.

6. Apparatus according to claim 5, wherein said frame is formed with a guide slot in which said common pivot of said links is slidably guided; and said operating means includes a roll, fitted to said common pivot; and, cooperating with said roll, a handle lever, pivoted intermediate its ends to said frame and having at one end thereof adjacent said roll a cam face engaging said roll.

'7. Apparatus according to claim 3, and including a handle lever, pivoted intermediate its ends to said frame and having a handle on one end and `a lug on the other end; :a straight link and a curved link, each pivoted at one end to said lug at points spaced from each other and to a respective one of said double .arm levers at the other end so that in an inoperative position of the apparatus the lug side end lof said straight link extends into the hollow of said curved link while the pivots of the two links on the lug are positioned in a vertical row laterally of the pivot of the handle lever, but in an operative position of the apparatus the pivots of the two links on the lug are positioned in a horizontal row below the pivot of the handle lever.

8. Apparatus :according to claim 7, wherein said central die means has a bottom 'face and two side faces and is located with its bottom face below said support shafts of said double arm levers and the side faces of said central die means have bow shaped recesses ldefined by cylindrical side faces having respectively an axis coinciding with the axis of the nearest support shaft.

9. Apparatus according to claim 3, including an eccentric roll located between one end of said double arm levers with cam means formed along parts of sai-d faces thereof, which cam means are exerting a separating force upon said one end of said double arm levers, resulting in a strip `gripping action of the other ends; and including a spring means attached to said levers for counteracting said separating force.

lll. Apparatus according to claim 9, wherein said roll is formed with `a T-shaped groove at its periphery; andV wherein said central die means is vertically slidable below said roll and guided by an upper portion thereof in said groove.

l1. Apparatus according to claim 1 wherein said central die rneans comprises two parts :and mounting means mounting said parts movably with respect to each other.

12. Apparatus according to claim 11, wherein said two parts of said central die means are so mounted on said mounting means las to include between themselves a gap of variable width.

13. Apparatus according to claim l2, wherein said central die means is so -movably mounted on said mounting means for movement lbetween an operative and an inoperative position that the overall width -of said die means is a maximum in the operative position and a minimum in the inoperative position.

30 14. Apparatus according to claim 1, wherein a plurality of irst and second Adie means are arranged on said frame spaced in one direction from each other so as to form simultaneously a plurality of fastenings, spaced longitudinally on the overlapping ends of said metal strip.

15. Apparatus according to claim l, including a cutoff means larranged on said iframe at a distance from said die means and including means for tensioning of said metal strip, said tensioning means bein-g located even farther away from said dies and at a distance from the cuto means on said frame.

References Cited by the Examiner UNITED STATES PATENTS 4 2,076,276 4/1937 Porter l40-93.2 o 2,077,491 4/ 1937 Perrelet 140--93-2 3,144,888 8/1964 Palmer 140--932 3,194,281 7/1965 Frey et al. 81-9.1

CHARLES W. LANHAM, Primary Examiner.

L. A. LARSON, Assistant Examiner'. 

1. APPARATUS FOR FASTENING OVERLAPPING ENDS OF METAL STRIP WRAPPED AROUND A PACKAGE BY MEANS OF AT LEAST ONE FASTENING CATCH, COMPRISING, IN COMBINATION, A FRAME; AT LEAST ONE PAIR OF FIRST DIE MEANS PIVOTALLY MOUNTED SPACED FROM EACH OTHER ON SAID FRAME AND HAVING STRIP ENGAGING FACE PORTIONS ADAPTED TO ENGAGE THE OVERLAPPING STRIPS AT ONE FACE THEREOF; A THIRD DIE MEANS CARRIED BY SAID FRAME AND ARRANGED SUBSTANTIALLY CENTRALLY BETWEEN SAID PAIR OF FIRST DIE MEANS AND HAVING AN END FACE SMALLER THAN THE WIDTH OF SAID OVERLAPPING STRIPS, AND ADAPTED TO ENGAGE SAID OVERLAPPING STRIPS ON A FACE THEREOF OPPOSITE SAID ONE FACE; AND MEANS CARRIED BY SAID FRAME AND COOPERATING WITH SAID DIE MEANS FOR MOVING THE LATTER RELATIVE TO EACH OTER IN SUCH A MANNER THAT SAID FACE PORTIONS OF SAID FIRST DIE MEANS MOVE BEYOND SAID END FACE OF SAID THIRD DIE MEANS SO THAT THE LATTER FORMS TWO SLITS THROUGH SAID OVERLAPPING STRIPS EXTENDING SUBSTANTIALLY IN LONGITUDINALLY DIRECTION OF SAID STRIPS SPACED FROM LONGITUDINAL EDGES THEREOF AND PRESSES OUT WEBS BETWEEN SAID SLITS THROUGH SAID OVERLAPPING STRIPS. 